‘However, we believe offering bigger bags at reduced fees will encourage more customers to consider checking in a bag, which will reduce the high volume of customers we have with two carry-on bags at the boarding gates, which is causing flight delays due to large numbers of gate bag and cabin bag offloads.’

In a bad day for European shares with major indices all slipping, Ryanair’s share price was down 0.8 per cent, or €0.13 at €18.05, as of late morning.

The carrier said that only passengers who purchase priority boarding, which costs €5/£5 at the time of the flight booking or €/£6 afterwards, will be allowed to have two bags with them in the cabin.

The rest of the passengers will only be able to carry a small bag, although the airline will still continue to put the other bigger bag in the hold for free.

It comes as Ryanair continues to attract a growing number of customers thanks to its low fares.

Yesterday it said its traffic grew by 10 per cent last month to 12.7million passengers while load factor rose 1 per cent to 97 per cent.